have u guys heard about that? take a look! http://hk.f2.page.auctions.yahoo.com/hk/auction/b2730862?aucview=search
Wow, that is interesting, I wonder what performance is like? One disadvantage is that you don't get old shuttles you can use for drills.
an old thread: http://www.badmintoncentral.com/forums/showthread.php?t=13393&highlight=replaceable+shuttle
It was first invented and sold by Prince. Actually, the prince one is adjustable too. I think it's a good idea but the rubbized core can be improved further to give even better feel and durability.